The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Vehicle manufacturers are currently developing vehicles that use non-combustion power sources to generate tractive torque. Exemplary vehicles utilizing non-combustion power sources to generate tractive torque include electric vehicles, hybrid electric vehicles and hydraulic hybrid vehicles.
Hybrid vehicles can utilize a non-combustion power source to achieve improved fuel economy and reduced emission levels over vehicles that utilize only internal combustion engines to provide vehicle propulsion. Hybrid vehicles achieve improved fuel economy and reduced emission by selectively utilizing an internal combustion engine or the non-combustion power source. Exemplary vehicles having non-combustion power sources can convert electrical power through motor/generator units. Motor/generator units can function as a motor to convert electrical power from batteries to provide torque to the transmission, independent from torque input from the internal combustion engine. Motor/generator units can function as a generator to convert kinetic energy from the vehicle transmission to electrical power stored by the batteries. In particular, hybrid electric vehicles can utilize regenerative braking in which the hybrid electric vehicle's speed is reduced by converting kinetic energy from the moving vehicle to electrical power stored in the batteries.
By controlling motor and generator functionality of the motor/generator units, control systems can control the balance between electrical power and internal combustion power utilized by the powertrain. The control systems can maintain the batteries at a state of charge that is within calibrated upper and lower charging limits. The state of charge is a ratio of the amount of electrical charge of a battery to the charge capacity of the battery. The lower charging limit is calibrated such that the battery state of charge is sufficiently high such that the battery can provide a selected amount of torque to the transmission. The upper charging limit is calibrated such that the battery state of charge is sufficiently low to accept charge from regenerative braking.
Global positioning systems hereafter (‘GPS’) utilize satellites to transmit signals to provide positioning information to GPS devices. Vehicles can utilize the GPS devices to determine a current position on the earth along with related information such as a current speed and a current direction at which the GPS device is travelling.
Map databases include information relating to a geographic region and can perform navigation functions such as determining travel routes to guide a driver within the geographic region. The travel route can include roads, streets or any other type of thoroughfare.